Recently I’ve been searching for case insensitive version of substr_count in PHP. I haven’t found any elegant solution, so let me post the simple code that does the trick.
$vsegoslov=substr_count(strtolower($spunator), strtolower($keyword));
I know is’t a piece of dirty code, but I don’t know any other option to do this. You can count the number of substring occurrences using Regexp-based functions, but if you don’t want to deal with them, that seems to be the fastest option for case insensitive substr_count.